Foot valve



Oct. 16,1934.

W. H. D. BRoUsE FOOT VALVE Filed Feb. 4, 1951 Patented Oct. 16, 1934more!) sures ears i FiCE FOOT VALVE Application February 4, 1931, SerialNo. 513,365

8 Claims.

The principal objects of the invention are, to overcome the difficultiesmet with in attempting to maintain a constant level of fluid in fluiddispensing systems, thereby facilitating accurate measurement at alltimes, and further, to provide a valve of the mercury seal type whichwill allow the escape of pressures in excess of the normal hydrostatichead, and will ensure the maintenance of an effective body of mercury ini the sealing pocket.

The principal features of the invention consist in the novelconstruction of a tapered tubular valve engaging a tapered tubular inletand sealed at the bottom end in a mercury seal, whereby the mercury ifforced upwardly from the sealing pocket by an excessive back pressure isintercepted and returned to the sealing pocket.

In the accompanying drawing,-Figure 1 is a verticalmid-sectional view ofa foot valve constructed in accordance with this'invention showing thevalve in the closedposition.

Figure 2 is a view similar to Figure 1 showing the valve open.

Figure 3 is a cross section taken on the line 3-3 of Figure 1.

In the operation of fluid dispensing apparatus, such as gasoline pumps,it is found that the ordinary types of check valves, used at the bottomof the supply pipe leading from the tank,

30, will not retain the column of liquid in the stand pipe, pump andmeter with the result that air pockets are formed and when the device isused, after resting for a substantial period the air pockets createdtherein hinder an accurate meas 35, urement of the fluid.

The most successful means proposed for over-;

coming this detrimental defect is a mercury sealed valve in which atapered tubular valving member encloses a tapered tubular inlet and issealed in a body of mercury arranged at the bottom of the valving memberbut it is found that conditions arise in the practical use of thesevalves that destroy the sealing effect of the mercury and in fact removethe mercury at least in part,

from the sealing pocket.

The present invention has eifectively eliminated these difficulties' andthe improved construction is illustrated in the accompanying drawing inwhich the body of the valve is in the form of a metal cylinder 1 havingfeet 2 extending from the bottom end to support the cylinder clear ofthe bottom of the tank in which the valve is placed.

A tapered tube 3 is formed with a flange 4 at the bottom end which issecurely sealed to the inner wall of the cylinder 1 above thefeet 2. Theupper end 5 of the tube 3 is open.

A tapered tubular valve member 6 is arranged to encircle thetube 3 andis provided with an enlarged closed end 7 which encloses the open upperend 5 of the tube 3, the enlargement extending well below the upper endof said inner tube and forminga recess surrounding the inlet tube.

A small tube 8 pierces the underside of the enlarged end '7 of the valve6 and is sealed therein and extends downwardly to the bottom end of thevalve providing a conduit from the recess to the sealing pocket.

A small quantity of mercury 9 is arranged in the pocket formed betweenthe bottom end of the inlet tube 3 and the casing 1 and seals the bottomend of the valve 6 andtube 8 secured thereto. The valve 6 is supportedslightly above the flange 4 and with its inner tapered surface justclear of the tapered outer surface of the inlet tube 3 and the mercuryfiow s around the free edge of the valve in a perfect seal which willeffectively hold the pressure of the normal hydrostatic column of fluidthereabove.

A collar 10 secured in the top of the cylinder 1 is threaded on to thestand pipe 11 which preferably projects a short distance below thecollar and forms an annular recess 12 which prevents the escape of themercury from the foot. valve while being handled prior to its beingplaced in the tank.

A spider 13 is threaded into the inner end of the pipe 11 and supports acheck valve 14 the stem 15 of which extends below the spider and 94 isprovided with a stop block 16 Which forms, a limit stop for the upwardmovement of the valve 6. This stop valve checks the back flow of fluidin the stand pipe immediately on the cessation of operation of the pumpconnected with the 95 stand pipe.

It has been found in the use of mercury sealed valves previouslyproposed that abnormal condij tions arising in the stand pipe above thefoot valve and creating pressures greater than that of thenormalhydrostatic column caused the mer-v cury to be driven from thesealing pocket up-- wardly between the inlet tube and the tubular valveand as the inner wall of such valves extended above the top of the inlettube the mercury flowed into the tank and the valve became useless.

In the construction of the valve herein shown the mercury when forcedupwardly between the valve 6 and tube 3 and the tube 8 flows into theenlargement 7 of the valve where it is intercepted and permits theescape of the excess pressure, the mercury then flowing back to thesealing pocket, thus enabling the continual reestablishment of the sealto support the fluid column for which the valve is designed.

The result of this means for intercepting the mercury and returning itto the sealing pocket is that while any excess pressure exists in thecolumn above the foot valve it will work its way between the valve 6 andtube 3 escaping to the tank without detrimentally affecting the mercuryseal.

The valve 14 is provided to check the flow of the fluid due to excesspressure thereby relieving the mercury seal from undue disturbance andallowing the excess pressure to equalize gradually as the liquid filtersthrough to the lower chamber.

A suitable screen 17 is arranged at the bottom of the cylinder 1 toarrest particles of grit or other foreign matter and the clearancebetween the valve 6 and metal tube 3 is such that any foreign particlespassing the screen will not lodge between said valve and tube but willcarry freely therethrough.

The device is extremely simple and inexpensive to build as no closefitting surfaces are required and it is found that it will eifectivelyretain the lightest fluids indefinitely and it operates auto maticallyand without loss of fluid.

In the form of the invention shown the inlet tube and valve are showntapered but it must be understood that they may be of cylindrical orother shape without departing from the spirit of the invention.

What I claim as my invention is:-

1. A foot valve having a tubular inlet surrounded by a sealing pocket, asealing fluid in said pocket, 2. displaceable tubular valving memberenclosing said tubular inlet and movable into and out of sealingrelation with said tubular inlet and said sealing fluid, said valvebeing recessed on the inner side adjacent the upper end thereof toreceive upwardly-displaced sealing fluid, and a conduit connecting saidvalve recess to said pocket.

2. A foot valve having a tubular inlet surrounded by a sealing pocket, asealing fluid in said pocket, a tubular valve enclosing said tubularinlet having its bottom edge sealed in said sealing fluid and having anenlarged upper end forming a recess surrounding the upper end of theinlet tube with its bottom normally below the top of the inlet tube, anda tube opening into said recess and extending down to the bottom of thevalve.

3. A foot valve having a tubular inlet surrounded by a sealing pocket, asealing fluid in said pocket, a tubular valve enclosing said tubularinlet having its bottom edge sealed in said sealing fluid and having anenlarged closed upper end enclosing the upper end of said inlet andhaving its bottom encircling said inlet tube nor- -mally below its upperextremity, and a tube opening into said enlarged upper end and extendingdownwardly and entering said fluid seal. 4. A foot valve comprising acylindrical casing, an inlet tube extending upwardly within said casingand forming an annular sealing pocket, a mercury seal in said pocket, aring secured in the top of said casing, a stand pipe secured in andextending below said ring and forming a seal, a tubular valve enclosingsaid inlet tube, and means forming part of said valve surrounding theupper end of said inlet tube adapted to intercept a sealing fluid anddirect it back to said sealing pocket.

5. A valve comprising a jacket, a frusto-conically shaped inlet piperising from the bottom of the jacket and extending upwardly therewithin,frusto-conically shaped bell receiving the pipe and normally seatedthereon, a closed overflow head carried by the upper end of the bell andenclosing the upper end of the inlet pipe, said upper end of the inletpipe projecting within the overflow head above the bottom thereof in theseated position of the bell, a liquid contained in the lower end of thejacket, said liquid having a relatively high specific gravity and saidbell having the lower end thereof normally immersed in the liquid, and apassage extending from the lower part of the head and having the lowerend thereof normally immersed in the liquid.

6. A valve comprising a jacket having the upper end thereof providedwith an outlet opening, a frusto-conically shaped inlet pipe risingcentrally within the jacket from the bottom thereof, a liquid having arelatively high specific gravity contained in the lower end of thejacket, a frustoconically shaped bell surrounding and normally seated onthe inlet pipe and having the lower end thereof in the seated positionof the bell immersed in the liquid and the upper end thereof stoppingshort of the upper end of the inlet pipe, a closed overflow head carriedby the upper end of the bell and enclosing the upper end of the inletpipe, a pipe leading from the bottom of the head and having the lowerend thereof immersed in the liquid in the seated position of the bell,and means for limiting the upward travel of the head.

'7. A foot valve having a tubular inlet surrounded by a sealing pocket,a sealing fluid in said pocket, a tubular valving member enclosing saidtubular inlet and movable into and out of sealing relation with saidtubular inlet and said sealing fluid, and means forming a cavity totemporarily receive sealing fluid forced upwardly between the'inlet andvalve, said cavity having a tubular connection with the sealing pocket.

8. A foot valve having a tubular inlet surrounded by a sealing pocket,said pocket having a sealing fluid therein, a valve member surroundingsaid tubular inlet in spaced relation therewith and sealingly engaged atthe bottom by said sealing fluid, said fluid being adapted to riseexcessively in said space under abnormal pressure conditions, and meansnormally disposed below the inlet top for temporarily receiving theexcessive displacement of said fluid during the abnormal pressurecondition to prevent same from overflowing the top of said tubularinlet, said receiving means having return communication with saidsealing pocket independent of said space.

WILLIAM H. D. BROUSE.

